I had a '11 ecoboost, a '13 and now a '17. The '17 gets 1-1.5 mpg better than the first gen. This is due to port injection being added and the 10 speed.
Pulling my 26' GD Reflection 22rk I get 9-9.5 mpg driving 63 mph. With my '16 SD and driving closer to 70 I get 10 mpg. Not a lot of difference any more between a diesel and the ecoboost for loads of this weight. If I slowed down with the SD to 63 like with the F150 I would expect maybe 11 mpg
The big difference is the wind. The SD is way more stable in high winds. I took my 32' GD 29rs to Colorado with the SD and would probably never try that with the F150. On the other hand the F150 rides better and gets better fuel economy unloaded in both highway and city
